org.apache.commons.collections4
Class FactoryUtils

java.lang.Object
  extended by org.apache.commons.collections4.FactoryUtils

public class FactoryUtils
extends Object

FactoryUtils provides reference implementations and utilities for the Factory functor interface. The supplied factories are:

All the supplied factories are Serializable.

Since:
3.0
Version:
$Id: FactoryUtils.java 1477779 2013-04-30 18:55:24Z tn $

Method Summary
static
<T> Factory<T>
constantFactory(T constantToReturn)
          Creates a Factory that will return the same object each time the factory is used.
static
<T> Factory<T>
exceptionFactory()
          Gets a Factory that always throws an exception.
static
<T> Factory<T>
instantiateFactory(Class<T> classToInstantiate)
          Creates a Factory that can create objects of a specific type using a no-args constructor.
static
<T> Factory<T>
instantiateFactory(Class<T> classToInstantiate, Class<?>[] paramTypes, Object[] args)
          Creates a Factory that can create objects of a specific type using the arguments specified to this method.
static
<T> Factory<T>
nullFactory()
          Gets a Factory that will return null each time the factory is used.
static
<T> Factory<T>
prototypeFactory(T prototype)
          Creates a Factory that will return a clone of the same prototype object each time the factory is used.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

exceptionFactory

public static <T> Factory<T> exceptionFactory()
Gets a Factory that always throws an exception. This could be useful during testing as a placeholder.

Type Parameters:
T - the type that the factory creates
Returns:
the factory
See Also:
ExceptionFactory

nullFactory

public static <T> Factory<T> nullFactory()
Gets a Factory that will return null each time the factory is used. This could be useful during testing as a placeholder.

Type Parameters:
T - the "type" of null object the factory should return.
Returns:
the factory
See Also:
ConstantFactory

constantFactory

public static <T> Factory<T> constantFactory(T constantToReturn)
Creates a Factory that will return the same object each time the factory is used. No check is made that the object is immutable. In general, only immutable objects should use the constant factory. Mutable objects should use the prototype factory.

Type Parameters:
T - the type that the factory creates
Parameters:
constantToReturn - the constant object to return each time in the factory
Returns:
the constant factory.
See Also:
ConstantFactory

prototypeFactory

public static <T> Factory<T> prototypeFactory(T prototype)
Creates a Factory that will return a clone of the same prototype object each time the factory is used. The prototype will be cloned using one of these techniques (in order):

instantiateFactory

public static <T> Factory<T> instantiateFactory(Class<T> classToInstantiate)
Creates a Factory that can create objects of a specific type using a no-args constructor.

Type Parameters:
T - the type that the factory creates
Parameters:
classToInstantiate - the Class to instantiate each time in the factory
Returns:
the reflection factory
Throws:
IllegalArgumentException - if the classToInstantiate is null
See Also:
InstantiateFactory

instantiateFactory

public static <T> Factory<T> instantiateFactory(Class<T> classToInstantiate,
                                                Class<?>[] paramTypes,
                                                Object[] args)
Creates a Factory that can create objects of a specific type using the arguments specified to this method.

Type Parameters:
T - the type that the factory creates
Parameters:
classToInstantiate - the Class to instantiate each time in the factory
paramTypes - parameter types for the constructor, can be null
args - the arguments to pass to the constructor, can be null
Returns:
the reflection factory
Throws:
IllegalArgumentException - if the classToInstantiate is null
IllegalArgumentException - if the paramTypes and args don't match
IllegalArgumentException - if the constructor doesn't exist
See Also:
InstantiateFactory


Copyright © 2001–2013 The Apache Software Foundation. All rights reserved.